KRS 421.030

A Commonwealth's witness in a felony case who resides in another state shall be allowed his necessary expenses in addition to the per diem, but no such allowance shall be made unless the judge of the court has made an order based upon the personal knowledge of the Circuit Judge or upon information showing that the testimony of the witness is material to the state, requiring the attendance of the witness. The expense and per diem shall be allowed by the Circuit Court and certified to the circuit clerk for payment.